There are many well-known devices for delivering constant volumes of liquids such as beverage bottling line fillers, drink dispensers, and refrigerator ice makers. These are static pressure devices sensitive to the pressure of a column of liquid or actuated by a timer. Other known devices include probe sensors able to monitor the level of a liquid entering a container of set volume.
The liquid dispensing devices described above have a series of unremediable drawbacks including relatively high production costs, inaccurate operation, poor durability, and non-uniform delivery volumes.